1. Field of the Invention
The present invention relates to an electrical connection testing device and to an electrical connection testing method for terminal fittings accommodated in a connector.
2. Description of the Related Art
Electrical connection testing devices are used to test electrical connections of terminal fittings that are accommodated in cavities of a connector. The connector has an engaging side, and the cavities have through openings at the engaging side for receiving the terminal fittings of a mating connector. The typical prior art electrical testing device functions by inserting testing probes into the through openings of the cavities at the engaging side of the connector and bringing the leading ends of the probes into contact with the terminal fittings that are locked in the cavities.
Female terminal fittings present a problem with the above-described electrical connection devices because only hollow portions of the female terminal fittings can be seen from the probe inserting side and because end surfaces of the female terminal fittings that are contacted by the probes cannot be seen. Further, the probes are inserted toward the terminal fittings in the same direction as the inserting direction of the mating terminal fittings, and hence the probes may damage the terminal fittings and/or the connector. Accordingly problems of reliability in electrical contact and connection precision may arise during connection with a mating connector.
In view of the above, electrical connecting testing devices for female terminal fittings typically are of the side probe type. More particularly, testing holes are formed in side walls of a connector housing and extend in a direction normal to a terminal inserting direction. The testing probes then are inserted through the testing holes in the side walls instead of being inserted through the openings at the leading ends of cavities. Thus, the testing probes contact the sides of the terminal fittings.
The applicant of the present invention proposed an electrical connection testing apparatus of the side probe type, as shown in FIG. 17 of Japanese Unexamined Patent Publication No. 6-258373. This device is constructed such that probes 2 are inserted into testing holes 1a formed in one side wall of a connector 1. The probes 2 are L-shaped. Leading ends of the probes 2 are bent to extend down and are inserted into the testing holes 1a. 
The above-described testing apparatus has testing holes 1a that can be formed only in one side wall (upper wall in FIG. 8) of the connector 1. Thus, only one stage of cavities can be provided in the connector 1. Many connectors are formed with cavities arrayed at two stages, and the above device cannot be applied to such connectors.
In view of the above problem, an object of the present invention is to provide an electrical connection testing device of the side probe type and an electrical connection method which allow for an easy testing of two stage connectors.
The subject invention is directed to an electrical connection testing device for testing electrical connections of terminal fittings in a connector. The testing is carried out by inserting testing probes at least partly through testing holes formed in side walls of a connector housing. The testing holes extend at an angle different from 0xc2x0 or 180xc2x0 to a mating direction of the terminal fittings with mating terminal fittings, and preferably substantially normal thereto. Thus, the testing probes can be brought elastically into contact with side surfaces of the terminal fittings of the connector.
The electrical connection testing device comprises a connector holder that is adapted to hold the connector. The connector holder is formed with probe insertion holes through which the probes can be inserted for contact with the terminal fittings of the connector.
The electrical connection testing device further includes first and second probe holders that carry the respective probes. A relative movement mechanism is provided for displacing the first probe holder, the second probe holder and/or the connector holder with respect to each other to insert the probes into the probe insertion holes and into contact with the terminal fittings of the held connector.
The testing device may comprise a base to which the first probe holder is secured. The connector holder and the second probe holder may be provided successively on the base for movement toward and away from the first probe holder.
The relative displacement mechanism preferably comprises a pushing mechanism for pushing a receiving surface of one of the probe holders at a side opposite from the connector holder. For example, the second probe holder and the connector holder may be moved toward the first probe holder by moving the pushing mechanism toward the second probe holder. This movement positions the probes at testing positions where the probes can be inserted into testing holes of a connector from substantially opposite sides.
The connector holder may be formed with opposite side walls that have probe insertion holes, and the first and second probe holders may be arranged to face the opposite side walls of the connector holder. The pushing mechanism may be operative to push the second probe holder and the connector holder toward the first probe holder for inserting the probes into testing holes of a connector from opposite sides. Accordingly, the probes are brought into contact with the terminal fittings at the opposite sides to conduct an electrical connection test merely by having the pushing mechanism move the second probe holder toward the first probe holder and into the testing position. Thus operability can be improved.
Upon completion of a test, the connector holder and the second probe holder can be moved by a linking or pushing mechanism from the testing positions to retracted positions so that the tested connector can be removed from the connector holder and replaced by another connector. Specifically, the pushing mechanism is at its retracted position when the connector is placed into the connector holder. Accordingly, the probe holders and the connector holder also are at retracted positions and away from each other in this state and wait on standby at such positions so that they do not interfere with the connector that is being inserted or taken out. The pushing mechanism then exerts forces on the receiving surface of the second probe holder and pushes the second probe holder toward the first probe holder after the next connector is placed in the connector holder. Thus, the second probe holder interferes with one side of the connector holder to push the connector holder toward the first probe holder. Consequently, spaces between the first probe holder and the connector holder and between the connector holder and the second probe holder are narrowed to reach the specified testing positions. In these positions, the leading ends of the probes are inserted through the probe insertion holes of the connector holder, into the testing holes of the connector and into elastic contact with the respective terminal fittings to conduct an electrical connection test.
The pushing mechanism is moved away from the second probe holder after the electrical connection test, and the linking mechanism returns the connector holder and the second probe holder to the retracted positions. Thus, the respective probes are withdrawn from the testing holes of the connector, and the connector can be taken out of the connector holder.
The pushing mechanism preferably comprises a lever pivotally mounted at an end of a base or at the connector holder. A cam of the lever pushes the receiving surface of the second probe holder and/or a receiving surface of the first probe holder as the operable lever is pivoted.
The relative displacement mechanism preferably comprises a retraction linking mechanism for moving the second probe holder and the connector holder together to retracted positions where the connector can be mounted into and taken out of the connector holder. The retraction linking mechanism preferably is operated by moving the pushing mechanism away from the second probe holder. Specifically, the retraction linking mechanism may comprise springs between the first probe holder and the connector holder and between the connector holder and the second probe holder for biasing the holders away from each other. A pushing force on the second probe holder is released by moving the pushing mechanism away from the second probe holder. As a result, the first probe holder and the connector holder, and the connector holder and the second probe holder are separated from each other and move together to the retracted positions by the biasing action of the springs.
The retraction linking mechanism may alternatively comprise a first link between the connector holder and the second probe holder and a second link between the second probe holder and the pushing mechanism. In such a case, no spring biases the second probe holder and the connector holder to the retracted positions. Accordingly, no large force is required by the pushing mechanism to move the second probe holder and the connector holder to the testing positions, thereby improving operability.
Preferably, at least one of the first and second probe holders comprises a stopper for preventing relative movements of the first and second probe holders to the testing positions. The stopper may function by interfering with a retainer that is mounted on the connector, and preferably on a terminal inserting surface of the connector. More particularly, the stopper may interfere with the retainer when the retainer is insufficiently inserted into the connector. In the case that the retainer of the connector is insufficiently inserted, the second probe holder and the connector holder cannot be moved to the testing positions since the stopper contacts portions of the retainer projecting from the rear surface of the connector in the connector holder. Thus, the electrical connection test cannot be conducted since the probes are not in contact with the terminal fittings of the connector. Thus an insufficiently inserted state of the retainer is detected. The stopper is in a position to block an insertion path of the connector into the connector holder when the second probe holder and the connector holder are in the testing positions. This prevents the leading ends of the probes from being damaged by forcible mounting of the connector into the connector holder.
According to a further preferred embodiment, a pair of probe holders is arranged to move toward and away from the opposite side surfaces of the connector holder.
Preferably, the relative movement mechanism comprises springs for biasing the probe holders toward the connector holder and toward testing positions where the probes are inserted through the testing holes of the connector in the connector holder.
The relative movement mechanism preferably comprises a cam that can be rotated or pivoted about one point as a fulcrum. The cam is formed with two pushing surfaces that project in substantially opposite directions with the fulcrum as a center. The cam is provided on one side wall of the connector holder, and the probe holders are formed with guide surfaces with which the corresponding pushing surfaces can come into contact,
Rotation of the cam causes the pushing surfaces of the cam to push the guide surfaces of the probe holders. Thus, the probe holders move away from the connector holder, preferably against biasing forces of the springs, to retracted positions where the connector can be inserted at least partly into and taken out of the connector holder.
Operability of the above-described embodiment can be improved since the probe holders are moved to the testing positions by the biasing forces of the springs and to the retracted positions by the rotation of the cam when the connector is to be accommodated into the connector holder. Specifically, when the connector is to be accommodated into the connector holder, the guide surfaces of the probe holders are pushed by the pushing surfaces against the biasing forces of the springs as the cam is rotated, with the result that the probe holders are moved to the retracted positions away from the connector holder and the probes wait on standby at positions where they do not interfere with the connector that is being accommodated or taken out. After the connector is accommodated, a rotating force of the cam is released. Accordingly, the probe holders are moved toward the connector holder by the biasing forces of the springs, the leading ends of the probes are inserted into the testing holes of the connector through the probe insertion holes of the connector holder and are elastically brought into contact with the respective terminal fittings to conduct an electrical connection test. If the cam is rotated again after the electrical connection test, the probes are withdrawn from the testing holes of the connector. Thus, the connector can be taken out of the connector holder.
Preferably, the cam is secured to a lever pivotal about the fulcrum and is rotated or pivoted by a pivotal movement of the operable lever. With such an arrangement, the cam rotating operation for moving the probe holders to the retracted positions by the lever action can be manually performed without any difficulty.
According to the invention, there is further provided an electrical connection testing method for testing electrical connections of terminal fittings that are accommodated at least partly in a connector. The method comprises at least partly inserting a connector that has a connector housing with side walls. Testing holes are formed in side walls of the connector housing and extend at an angle different from 0xc2x0 or 180xc2x0, and preferably substantially normal to a terminal mating direction of the terminal fittings with mating terminal fittings. The method then comprises inserting the connector into the connector holder formed with probe insertion holes that substantially correspond to the testing holes;
The method continues by relatively displacing a first probe holder, a second probe holder and/or the connector holder with respect to each other from a retracted position to a testing position so as to insert the probes into the probe insertion holes and the testing holes for contact with the terminal fittings of the held connector. The method then includes testing the terminals fittings in the connector by means of the probes.
The inventive electrical connection testing device and method can be applied suitably for female terminal fittings. In other words, the probes cannot be brought easily into contact with the female terminal fittings using the prior art electrical connection testing device. However, if the testing holes are formed in positions of the connector housing corresponding to portions of the female terminal fittings except barrel portions, the leading ends of the probes inserted through the testing holes can be brought securely and easily into contact with the side surfaces of the female terminal fittings.
These and other objects, features and advantages of the present invention will become apparent upon reading of the following detailed description of preferred embodiments and accompanying drawings. It should be understood that even though embodiments are separately described, single features thereof may be combined to additional embodiments.